Authors

Article Title

DOI

10.5642/aliso.19971602.05

First Page

103

Last Page

112

Abstract

Saving a species from extinction may not insure that its future will continue as before, even when the surviving population is in a wild habitat. Former selection forces may be missing or replaced by others so that the species develops along a different evolutionary pathway. Such disruption of evolutionary direction may be particularly important for island taxa given that modification by humans and their introduced organisms is making many islands more similar to continental habitats. In restoring habitats for island species, special attention should therefore be given to identify ing the major selective forces likely to have been operating during the evolution of those species. It will not always be practical to reinstate all these selective forces. However, there are sometimes opportunities to restore, or reconstruct by species substitution, the biotic selection formerly brought about by herbi vores, predators, competitors, pollinators and seed dispersers. Systems restored in this way will not be authentic replicas but may function more like systems of the past than those operating at present. Data from New Zealand, where restorative action has been taken on more than 40 islands, are used to examine these general principles. The ongoing restoration of Round Island, Mauritius, is used to illustrate the kinds of questions that this approach generates: should species thought likely to have once been present on Round Island be re-established?; should a giant tortoise be introduced to the island to substitute for the extinct species of tortoise that was lost last century?